Apparatus for the curettage or exeresis of biological tissues by means of an instrument vibrating at ultrasound frequencies

ABSTRACT

Ultrasound apparatus intended for the curettage or exeresis of biological tissues by irrigation of a liquid subject to cavitation and by suction of the disaggregated tissues, the apparatus comprising a hand-piece containing a transducer which is mechanically coupled to a vibrating instrument or sonotrode. Said apparatus is characterized in that the handpiece (1) is traversed in the longitudinal direction by a section conduit (15,24) connected on the one hand to a suction connector (3) provided at the backend of the end piece (1), and one the other hand to the internal part of the suction sonotrode (17).

The present invention relates to an apparatus for the curettage orexeresis of biological tissues by an instrument vibrating at ultrasoundfrequencies, associated with one or more irrigating fluids placed incavitation and absorbed by a coaxial suction system.

Apparatus using ultrasounds for the treatment of surfaces have beenproposed for a long time. This is the case in industry, as in themedical field, particularly in dental surgery. The extreme rapidity ofthe ultrasound vibrations transmitted to an instrument makes it possibleto detach and reduce into fine particles deposits such as tartar.

Such an apparatus is all the more efficient as a projection of fluid orof abrasive powder can be added thereto, which erodes the part to bedetached which may then be recovered by a suction system.

Such a combination of means, namely projection of particles or offluid(s), ultrasounds applied to a tool and suction, is moreoverdescribed in U.S. Pat. No. 2,874,470. This patent demonstrates theinterest of this combination, for its efficiency and for its ergonomicadvantages.

The present invention takes up the combination of these means,irrigation and suction, adopting for each of these functions a coaxialconfiguration such as may be seen in U.S. Pat. No. 2,709,852 whichdescribes a dental apparatus, or in U.S. Pat. No. 3,089,790, whichdescribes a cleaning apparatus employing ultrasounds, with coaxialirrigation and suction.

In the surgical domain, apparatus do exist which take up this type ofconfiguration in the same manner and use the same combination of means.However, these apparatus, known under the name of ultrasound surgicalaspirators, present a certain number of drawbacks.

On the one hand, the hand-piece does not entirely integrate the circuitsof the fluids, particularly the suction conduit and the irrigationconduit with, as consequence, an exaggerated increase in the diameter ofthis hand-piece. Any delicate operation is thus rendered difficult andtiring for the operator. The magnetostriction used in the knownapparatus does not enable these drawbacks to be overcome.

On the other hand, the known technique of ultrasound surgical suctionhas the drawback of tearing the tissues in certain cases, in particularin the case of the suction being poorly adjusted. Conversely, in othercases, the destroying effect is insufficient and the process presentsrisks for the adjacent tissues in the case of exeresis of certaintumours, particularly cystic ones.

In such a known apparatus, there is no other solution, in the difficultcases requiring a highly efficient apparatus, than the reinforcement ofthe suction or of the ultrasounds applied to the single vibratinginstrument also called "sonotrode". In this latter case, the power maybe such that heating is considerable and the amplitude obtained at theend of the sonotrode may damage the adjacent tissues and vessels.

To this end, this ultrasound apparatus for the curettage or exeresis ofbiological tissues by irrigation of a liquid subjected to cavitation andby suction of the disaggregated tissue, comprising a hand-piececontaining a transducer which is mechanically coupled to a vibratinginstrument or sonotrode, is characterized in that the hand-piece istraversed right through, in the longitudinal direction, by a suctionconduit connected on the one hand to a suction connector located at therear end of the hand-piece and, on the other hand, to the internal partof the suction sonotrode.

The apparatus according to the invention has the advantages:

of integrating the circuits of the fluids from one end of the hand-pieceto the other, offering the possibility of having a large suctiondiameter;

of lightening to a maximum this hand-piece which is like a tube;

of having, thanks to the high yield of the piezo-electricity, a minimumheating of the assembly. Thanks to an automatic adaptation of theamplitude of the vibration of the hand-piece as a function of theresistance of the tissue encountered, it is possible to act efficientlyon any sort of tissue.

It is possible to use either washers in piezo-electric ceramicspolarized in the thickness, or a tube of piezo-electric ceramicspolarized radially, this having for advantage to clear to a maximum thevery interior of the transducer. This advantage makes it possible to beable to combine an assembly of means, including suction and irrigation,in a restricted volume, but it also enables other means such as a sightfor optical fiber and/or a laser beam, to be coaxially integrated.

The use of several sonotrodes fixed on the same transducer makes itpossible to modulate the cutting effect and to avoid any risk of tissuetear. The effect of cavitation is considerable due to the integration ofthe irrigation fluid in a sonotrode.

Various embodiments of the present invention will be describedhereinafter by way of non-limiting examples, with reference to theaccompanying drawing, in which:

FIG. 1 is a view in axial section of an apparatus according to theinvention.

FIGS. 2a, 2b, 2c are views in partial axial section of variousembodiments of the end parts of the sonotrodes.

FIG. 3 is a view in axial section of a simplified variant embodiment ofa hand-piece.

FIG. 4 is a view in transverse section made along line IV--IV of FIG. 3.

FIG. 5 is a view in elevation of a single sonotrode with outsidelongitudinal flow of the irrigation fluid.

FIG. 6 is a schematic view in elevation of a variant embodiment of asonotrode with outside helical flow of the irrigation fluid.

FIG. 7 is a schematic view in elevation of another variant embodiment ofa sonotrode with outside longitudinal flow of the irrigation fluid.

FIG. 8 is a view in partial axial section of a variant embodiment of theapparatus.

The apparatus according to the invention shown in FIG. 1 comprises, inconventional manner, a hand-piece 1 containing a generator of ultrasoundvibrations or transducer 5 extended, at its front end, by an elongatedinstrument 2 subjected to axial ultrasound vibrations and constituted byone or more coaxial sonotrodes. At its rear end, the hand-piece 1 bearsconnectors, namely a connector 3 connected to a source of vacuum, inorder to effect suction, and a connector 4 for admission of anirrigation fluid.

The transducer 5 comprises a tube 6 of piezo-electric ceramics which ismaintained blocked between a front part 7, of relatively large diameter,and a distance piece 8 blocked by means of tightening nuts 9, thetightening pressure being ensured by two prestress washers 10. Thepiezo-electric tube 6 is connected to the outside by electric connectingwires 11 which emerge from the rear end of the hand-piece 1. As may beseen in FIG. 1, the central part of the transducer 5 is hollow and itallows the through passage, through the hand-piece 1, of an irrigationfluid and of the suction current. In the non-limiting embodiment shownin FIG. 1, the transducer is axially traversed right through by an axialirrigation tube 12 which is connected, at its rear end, to the connector4 for admission of the irrigation fluid. This irrigation tube 12 is fastwith the front part 7 of the transducer 5 so as to be subjected to theultrasound vibrations, and this via a connecting piece 13. Thisconnecting piece 13 is pierced right through with a central conduit andit is connected, at its front part, to an axial tube 14 extending overthe whole length of the vibrating instrument 2. This tube 14 thusconstitutes an irrigation sonotrode of the apparatus.

Furthermore, the transducer 5 is traversed, right through, in the axialdirection, by at least one suction conduit 15 which is offset outwardlywith respect to the irrigation tube 12 and which communicates with thesuction connector 3. In the example illustrated in the drawing, thesuction conduit 15 is constituted by the internal volume of thetransducer 5 which surrounds the central irrigation tube 12. Thissuction conduit 15 communicates, via at least one hole 16 pierced rightthrough the connecting piece 13, with at least one suction conduitextending longitudinally inside the wall of the vibrating instrument 2which forms the suction sonotrode. The inner conduit of the suctionsonotrode 17 is in fact constituted, in this embodiment, by the volumesurrounding the central conduit of the irrigation sonotrode 14.

In the rear part of the hand-piece 1 is housed a connecting block 18which is connected to the rear end of the transducer 5, withinterposition of an 0-ring 19 and which is traversed axially by the rearpart of the irrigation tube 12 extending up to the irrigation connector4. Another O-ring 20 is disposed in the connecting block 8 around theirrigation tube 12 and it is maintained tightened by a stuffing box 21traversed by the irrigation tube 12 and screwed in the rear part of theconnecting block 18.

The two irrigation sonotrodes 14 and suction sonotrode 17 may terminate,at their front ends, either in the same transverse plane as illustratedin FIG. 2a, or in different transverse planes. In the case illustratedin FIG. 2b, the internal irrigation sonotrode 14 projects with respectto the outer suction sonotrode 17 whilst FIG. 2c shows the reversearrangement in which the outer suction sonotrode 17 extends beyond theinternal irrigation sonotrode 14. Furthermore, FIGS. 2a, 2b and 2c showthat the end parts of the sonotrodes are in bevelled form, the bevelledend part of the outer suction sonotrode 17 converging in the directionof the axis whilst the bevelled end part of the internal irrigationsonotrode 14 has a diverging form.

The different positions that the sonotrodes may occupy with respect toeach other, as well as their forms, have different effects on thetissues and thus on the efficiency of the apparatus.

In the case illustrated in FIG. 2a, i.e. when the ends of the twosonotrodes are located in the same transverse plane, it is possible toobtain an effect of fragmentation which is localized and on the surface.

In the case illustrated in FIG. 2b, i.e. when the internal irrigationsonotrode 14 passes beyond the outer suction sonotrode 17, thevibrations of the two sonotrodes 14 and 17 are phase-shifted withrespect to one another due to their different diameters, which has forits effect to obtain with the suction a phenomenon of shear of thetissues.

In the case illustrated in FIG. 2c, i.e. when the irrigation sonotrode14 is located inside the suction sonotrode 17 itself, a veritabletissular lysis is obtained which alters nothing in the selective cut ofthe vibrating instrument 2 at its end.

Thanks to the configuration with two sonotrodes 14 and 17 which has beendescribed hereinabove, a combined effect is obtained of two instrumentswith ultrasound vibrations which reinforces the cavitation and avoids,to be very efficient, having to increase the power of the transducer orof the suction. In order to be able to clear the vision of the operativefield, it is possible to arrange for the axis of the vibratinginstrument 2 no longer to be aligned with the axis of the hand-piece 1,as is shown in FIG. 1, but for it to form therewith an angle which mayrange from 0° to 90° with intermediate adaptation pieces to beconnected. A straight intermediate extension may also be employedbetween the hand-piece 1 and the instrument 2.

FIGS. 3 and 4 show a simplified variant of a hand-piece 1 obtainedthanks to the use of the piezo-electricity. In this case, the transducer5 uses, in place of a piezo-electric tube, an assembly of pellets 22mounted in series and tightened against one another by means of an axialtie-rod 23 and nuts 23a. As the transducer 5 forms a compact assemblywithout possibility of passage therethrough, the irrigation conduit 24and the suction conduit or conduits 25 are still provided inside thehand piece 11, but outside the transducer 5. More particularly, as maybe seen more readily in FIG. 4, the suction conduit 25 and irrigationconduit 24 are housed in the space available between the transducer 5and the cylindrical wall 26 of the hand-piece 1.

In the variant embodiment illustrated in FIG. 5, the apparatus accordingto the invention comprises a single sonotrode 27 for suction andirrigation, which is mechanically coupled, as in the preceding cases, tothe transducer housed in the hand-piece 1. This single sonotrode 27presents, on its lateral surface, one or more longitudinal grooves whichenable the irrigation liquid to go, under the effect of the ultrasounds,as far as the end of the sonotrode. At that point, the liquid is suckedinside the sonotrode 27 with the debris taken along, and the suctioncurrent flows axially inside the sonotrode 27 and through a conduit inthe hand-piece 1 up to the suction connector. Supply of irrigationliquid is effected by means of an annular connecting piece 28 which isfixed on the front end of the hand-piece 1 and which surrounds the baseof the sonotrode 27, leaving a free passage 29 between the connectingpiece 28 and the base of the sonotrode 27. This passage enables theirrigation liquid, which is conducted by a tube 30 opening out insidethe connecting piece 28, to flow on the longitudinal grooves of thesonotrode 27 in the direction of the end thereof.

FIG. 6 shows a variant embodiment of a single sonotrode 31 for suctionand irrigation which presents, on its lateral surface, at least onehelical thread 32 channelling the flow of the irrigation liquid which,as in the preceding case, goes, under the effect of the ultrasounds, inthe direction of the end of the sonotrode 31.

In the variant embodiment illustrated in FIG. 7, the single sonotrode 33for suction and irrigation comprises a hollow rod, of slightly conicalform, of which the central axial conduit is connected, through thehand-piece, to the suction connector and which bears, on its lateralsurface, one or more longitudinal irrigation tubes 34.

In the variant embodiment of the invention shown in FIG. 8, theapparatus which has been illustrated and described with reference toFIG. 1 is provided with a third coaxial sonotrode 35 which surrounds thesuction sonotrode 17, itself containing the irrigation sonotrode 14.This third sonotrode 35 forms an integral part of a base 36 which bearsa tube 37 for connection to a source of irrigation fluid and which isfixed, by any appropriate means and with interposition of a seal 38, onthe front part of the transducer 5. Such a device offers the advantageof allowing the path of several treatment liquids over a zone to betreated and this principle is particularly interesting when it isnecessary to place these liquids into presence at the last moment.

Furthermore, the apparatus according to the invention makes it possiblealso to transmit, right through the hand-piece 1 and the vibratinginstrument 2, a beam of hot light in order to obtain, for example, animmediate haemostasis. A bipolar sonotrode with diathermic effect aswell as a laser beam may be used, each of these effects being able to becombined.

We claim:
 1. Ultrasound apparatus for the curettage or exeresis ofbiological tissues by irrigation of a liquid subjected to cavitation andby suction of the disaggregated tissue, comprising:a hand-piececontaining a transducer which is mechanically coupled to a sonotrode; asuction conduit within said hand-piece having a front end and a rear endand extending therebetween in a longitudinal direction in saidhand-piece; a suction connector at the rear end of said hand-piece andconnected to the rear end of said suction conduit; a suction sonotrodein said hand-piece connected to the front end of said suction conduit;and means traversing longitudinally right through said hand-piece andsaid sonotrode for allowing the transmission therethrough of at leastone of a beam of hot light for illumination and/or of a cutting laserbeam, for treatment or haemostatis.
 2. An ultrasound apparatus for thecurettage or exeresis of biological tissues by irrigation of a liquidsubjected to cavitation and by suction of the disaggregated tissue,comprising:a hand-piece containing an ultrasonic transducer; two coaxialvibrating sonotrodes mechanically coupled to said transducer, saidsonotrodes having front ends located in planes transverse to saidhand-piece, and rear ends connected respectively to a suction connectorand to an irrigation conduit means including a pair of conduitsextending longitudinally in a space provided between the transducer anda wall of said handpiece.
 3. Apparatus according to claim 2, wherein oneof said sonotrodes is an inner irrigation sonotrode while the other ofsaid sonotrodes is an outer suction sonotrode.
 4. Apparatus according toclaim 2, said irrigation conduit means extends longitudinally rightthrough said hand-piece.
 5. Ultrasound apparatus for the curettage orexeresis of biological tissues by irrigation of a liquid subjected tocavitation and by suction of the disaggregated tissue, comprising:ahand-piece containing a transducer which is mechanically coupled to avibrating instrument; a suction conduit within said hand-piece having afront end and a rear end and extending therebetween in a longitudinaldirection is said hand-piece; a suction connector at the rear end ofsaid hand-piece and connected to the rear end of said suction conduit;sonotrode means in said hand-piece connected to the front end of saidsuction conduit for suctioning; and means longitudinally traversingthrough said vibrating instrument for allowing the transmissiontherethrough of a beam of hot light for illumination and/or of a cuttinglaser beam, for treatment or haemostatis.
 6. Apparatus according toclaim 5, wherein said sonotrode means includes a single suction andirrigation sonotrode, and irrigation conduit means extending over thesurface of said single suction and irrigation sonotrode, and saidconduit means being connected to the interior of a connecting piecefixed on the front part of said hand-piece, and a tube connected to saidconnecting piece for connecting said connecting piece to a source ofirrigation fluid, said connecting piece defining with the base of saidsingle suction and irrigation sonotrode a passage for the irrigationfluid towards the front end of said vibrating instrument.
 7. Apparatusaccording to claim 2, wherein said vibrating instrument is a sonotrode.8. Apparatus according to claim 5, wherein said single suction andirrigation sonotrode bears, on its lateral surface, longitudinal groovesensuring the path of the irrigation fluid.
 9. Apparatus according toclaim 5, wherein said single suction and irrigation sonotrode bears, onits lateral surface, at least one helical thread guiding the path of theirrigation fluid.
 10. Apparatus according to claim 5, wherein saidsingle suction and irrigation sonotrode bears, on its lateral surface,at least one longitudinal tube ensuring flow of the liquid of theirrigation fluid.
 11. Apparatus according to claim 5, wherein saidsonotrode means comprises at least two coaxial sonotrodes, one of saidsonotrodes being an outer suction sonotrode and the other being aninternal irrigation sonotrode.